Fireproofing compositions containing water-insoluble phosphorylamides, and articles fireproofed therewith



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smears; Patented Jam 8 1952 2 2 1 1 UN OFFICE FIREPROOFING COMPOSITIONS CONTAIN- ING 'WATER-INSOLUBLE PHOSPHORYL- AMIDES, AND ARTICLES FIREPROOFED THEREWITH John Tru'hl'ar, Clarendon Hills, and Athan A. Pantsios, Chicago, 111., assignors to Rudolf F. Hlavaty, Westchestcr, Ill.

No Drawing. Application March 25, 1949, Serial No. 83,514

This invention relates to a material for and a method of fireproofing. The material may be used for fireproofing many materials, natural or synthetics and their combinations. It may be used, for example nziiseetmfieesibregemeiez rial of any nature, whether the fibrous material is merely in fibrous form or woven or felted or 7 be flreproofed.

Another object of the invention is to provide a fireproofing material which is permanent in character and which cannot be removed by washing, weathering, or by the solvents used in-dry cleaning or by reaction of weather conditions, as it is permanent.

Another object is to provide a fireproofing material of such efficiency that relatively, small amounts of it will prove adequate for fireproofing and thus accomplish a saving in total weight of fireproofed material.

A further object is to provide a fireproofing agent which is non-corrosive and non-toxic, so that the agent itself and the material which has been treated with it can be freely and safely handled. 7

Other objects will appear from time to time throughout the specification'and claims.

A variety of fireproofing materials are now known and most of such materials have generally one or more of the following defects: They are ineificient and substantial weights are required. They are corrosive and toxic. They are not permanent in character.

It is present practice to apply by painting or otherwise relatively large amounts of metallic oxides as fireproofing agents. Among such oxides are those of tin, aluminum and antimony. Be cause each of these is relatively in'eificient, extremely large amounts are necessary to produce efl'ective fireproofing results. In the case of an-' timony oxide, which is probably the most efllcient, the weight which must be added to an ar ticle for fireproofing will be of the order of 50% of the weight of the article itself. Thus if a piece of canvas or tarpaulin or some other article untreated has a weight of 100 lbs. its weight will be 150 lbs. after treatment with antimony oxide. Antimony oxide" has the rather disad vantage that it, like arsenic oxide, is a cmnula'a 11Claims. (Cl. 26029.2)

tive poison and elaborate precautions must be taken in producing the material and in using it, and thus, also, materials which have been treated with antimony oxide are toxic and must be handled with extreme caution.

Another class of fireprooflng materials includes chlorinated waxes and resins which may be used along with or in combination with various metallic oxides for fireproofing. In the case of these materials also large quantities are required for efiectiveness and they have the further disadvantage that they are corrosive in character and form hydrochloric acid, particularly at elevated temperatures.

The firperoofing material of the present inven-' tion comprises the amides, imidesg d ii nidoamides of phosphoric ari'd thi'ophbs'phoric acids, as Well as the nitride of phosphoric acid. Tests have shown that these materials are excellent fire and flameproofing agents and that they are effective in very much smalleramounts than the metallic oxides used at present, such as the oxides of tin, aluminum and antimony. They have the further advantage that they are non-poisonous and non-corrosive and that they are insoluble in water and in most available solvents.

Phosphoric acid may be given the following structural formula:

OH O=POH 0H In this material it is possible to substitute ammonia for the three hydroxy groups by treating phosphoryltrichloride with dry ammonia and forming thus the triamide of phosphoric acid which has the following structural formula:

NH; 0=PNH2 NHa This latter material is usually known as phosphorylimidoamide and comprises a White powder insoluble in water and acids and only very slightl3 ailec'tedloy hot alkalies gpgn heati dtherr/whg phosphorylimidoamide loses a molecule of ammonia and the compound O=P=N is formed.

' This material is phosphorylnitride and comprises a white inert powder which forms a black glass at red heat.

In practice the fireproofing material of this invention is the water insoluble, chlorine free,

reaction product of phosphorus oxychloride with anhydrous ammonia. This reaction product consists of a mixture of phosphoryltriamide, phosphorylimidoamide and polyphosphorylamides. It ispossible, though very difficult, to separate the three components of the reaction product, but for the purpose of this invention it is not necessary since all three are powerful fireproofing agents. On the other hand, it is readily possible to control the proportion in which they are formed by controlling the conditions of the reaction; for example, when the reaction is affected at low temperatures, the phosphoryltriamide predominates in the reaction product, while higher temperatures favor the formation of the prosphorylimidoamide and polyphosphorylamides.

The existence of the polyphosphorylamides in the reaction described is indicated by results of experiments carried out by the inventors which do not pertain to the present invention. The evidence is not conclusive but indicative of their possible existence. The formation of the phosphoryltriamide and phosphorylimidoamide in the reaction oi. phosphorus oxychloride and anhydrous ammonia is a matter of record in the known technical literature. The differences discussed in the literature on the subject are further resolved by the assumption of the existence of the polyphosphorylamides. A probable structure for the polymeric amide may be:

P il l l vat mere H H H 'H The mixture of phosphoric acid amides which was just described. and which the inventors use as the fireproofing agent is a white amorphous inert material completely water insoluble. Mellor in his Authoritative Treatise of Inorganic Chemistry substantiates this view. 7

For the purpose of brevity the generic term phosphorylamides will be used throughout the specification and claims to indicate the mixture of phosphoric acid amides which is the reaction product of phosphorus oxychloride and anhydrous ammonia, as described above.

It is recognized today that fireproofing may be accomplished as a result of two actions: (1) the formation, upon heating, of a fire quenching gas such as ammonia, carbon dioxide or chlorine, which gas smothers the flame; and (2) the formation, upon heating, of a melted material which covers the combustible fibers or article and prevents burning.

The metallic oxides and some salts such as borax operate in the latter manner to produce, upon melting, a glass-like material. The ammonia and chlorine compounds act in the former manner to produce fire quenching gases.

The amides and imides of phosphoric and thiophosphoric acid are extremely effective because they partake of both methods of quenching fire. Upon heating a fire quenching gas is formed and also a glass-like material is produced as a result of melting, and this material covers the fibers or 7 f with Wbib. 1? i 2 ieqa qp e ts l 4 burning. The phosphorylnitride acts in the same way.

The following examples illustrate several uses of the material above described. The examples are given merely as typical of various uses and the invention is not limited to the particular examples given.

e Parts Phosphorylamides 30 Polyvinyl chloride 3 Acetone 67 Pentachlorphenol 0.1

Parts Phosphorylamides 25 Water Chlorinated paraflin 15. Light petroleum'solvent 8 Emulsifier 2 In this case the phosphorylamides are suspended in the water-in-oil emulsion from which they are applied on the material to be treated by spraying, dipping orroller coating. The chlorinated paraflin acts as a binder and since it is thermally unstable and upon decomposition hydrochloric acid is vformed, it further enhances the fireproofing quality of the mixture.

I III l 7 Parts Phosphorylamides 15 Water 25 Polyvinylchloride acetate copolymer 5 Dichlorethane 45 ilricresylphgephate 8 Eiifii ifier1 2 Here the vehicle for the phosphorylamides is an oil-in-Water emulsion. The binder is plasticized with tricresylphosphate, and both contribute to the fireproofing quality of the deposit.

' Parts Phosphorylamides 20 Water 45 Chlorinated naphthalene 10 Carbon tetrachloride 23 Emulsifier 2 This is another example of an oil-in-water emulsion using chlorinated napthalene as the thermally'unstable binder. The solvent used makes this emulsion safe to handle. In the same manner, other thermally unstable chlorinated organic compounds suitable as binders for the phosphorylamides can also be used. These could be neoprene, pentachlorobiphenyl, chlorinated, natural 70 or synthetic rubber, and chloropolystyrene.

r vParts Phosphorylamides 70 7.5, Chlorinated rubber w i a assesses An intimate mixtu-re of the two materials in fine powder form is dusted directly upon the fibers to be fireproofed. These are then h eated electronically to a temperature just high enough to soften the binder and thus fix the phosphorylamides permanently on the fibers. A slightpremoistening of the fibers with an atomized plasticizer like tricres-ylphosphite helps settle the powders and also flexibilize the deposit. "Thephosphite, in addition, inhibits hydrochloric acid formation. f

Parts Powdered phosphorylamides 75 Powdered polyvinylchloride acetate copolymer 25 This is another example of dry binding by means of heat.

The phosphorylamides, because of their nature, are preferably used with a binder. As indicated by the examples enumeratedabove,"thermally unstable chlorinated organic compounds v.are preferred because they are noncombustible. This should not be presumed to exclude other binders.

VII

Parts Phosphorylamides -I 50 Commercial polyvinyl acetate emulsion 45 Tricresylphosphate The polyvinyl acetate film alone supports fire but in the presence of the phosphorylamides it does not burn. On the other hand, the total effectiveness as a fireproofing mixture is much les than that of any of Examples I--VII, and the use of binders which support fire is recommended only when other considerations prevent the use of the thermally unstable chlorinated binders. Other film forming, water insoluble materials (or such as can be rendered water insoluble) may also be used. Among these are polystyrene emulsion, synthetic and natural latexes, and alkyd resin emulsions.

Examples VIII, IX and X illustrate the use of the phosphorylamides in typical fireproof surface coatings. Example VIII is a fireproof enamel; Example IX a fireproof paint; and Example X a fireproof lacquer.

The examples of surface coatings given above llO mer y ex ress. apic l suitable .PIPBQ P J LJE.

general a flameproof surface coating may be made in which the phosphorylamides constitute from 15% to 50% of the paint. The pigments used in these fireproof surface coatings are those normally used in the paint industry. Their choice depends upon the purpose they are to serve in the surface coating, andthey are generally chosen from the group of inorganic metallic oxides, carbonates, sulphides and sulphates such as titanium dioxide, lithopone, lead oxides and zinc oxides.

It is alsopossible to treat fibers, fabric sgetc in such a manner that the phosphorylamides are formed within and upon them. The reactants, dry gaseous ammonia and vapors of phosphoryltrichloride, are brought tog-ether upon the material to be treated wherein they react and deposit the phosphorylamides in and upon the material.

It should be pointed out, however, that even in this extreme case when the reaction takes place upon the fibers to deposit the fireproofing agents, there is nochemical interaction between the fibers and the phosphorylamides, andv the deposition is purely a physical one. No attemptis being made here, for example, to bringabou't chemical combination between the fibers and the reactants, and none takes place.

The materials treated by the products above mentioned have beenreferred to as being fireproofed. The result of the treatment is to make these materials greprg of and gam eproof. and also glowprop f, That is to say, the material treated,

when exposed in air to a flame, may be slowly consumed but if consumed no flame or glow is present, and the material itself will not support combustion. The absence of glow is important, because a glowing material which may be consumed without flame may nonetheless spread fire as a result of this glow by contact with untreated materials.

Any material, whether fiat goods, fibers or batting, when treated by any of the combinations of the examples given, becomes distinct and can readily be identified chemically as being fireproofed by means of the phosphorylamides. This is possible because of the insolubility of the phosphorylamides in all solvents. It is therefore possible to remove the phosphorylamides from the treated material and eliminate all other interfering substances and identify chemically the phosphorylamides.

The amount of phosphorylamides necessary satisfactorily to fireproof such materials may be as little as 10% by weight of the material, irrespective of any contribution of the binder to the total fireproofing effect. It is to be remembered that the binders proposed herein are in some cases not fireproof or fire resistant in themselves. However, as much as of phosphorylamides may be added without detrimental effect on the treated materials. In usual practice the total of the solids add on of 20% to 30% is satisfactory. The phosphorylamides may be mixed with or applied to a material to be fireproofed in almost any manner, either as the material is made or processed or after it has been made.

This application is a continuation-in-part of our co-pending application Serial No. 633,532, filed December '7, 1945, now abandoned.

We claim:

1. A fireproofing paint comprising 20-50% of the water insoluble reaction product of phosphorous oxychloride with anhydrous ammonia and 80-50% of normal paint ingredients includll ,QPE PEEUE Q.EXQFQ? E 5 winder-I.-.

WWW-rm eases soon i7 2. A fireproofing paint comprising 20-50% of the water insoluble reaction product of phosphorous oxychloride with anhydrous ammonia and 80-50% of normal paint ingredients, including pigment, resin and solvent; a

3. A fireproofing composition comprising 20- 50% of the water insoluble reaction product of phosphorous oxychlorlde with anhydrous ammonia suspended in 80-50% of a solution of thermally unstable chlorinated organic compounds as a binder.

4. A fireproofing composition comprising 50- 90% of the water insoluble reaction product of phosphorous oxychloride with anhydrous ammonia intimately mixed with 50-10% of thermally unstable chlorinated organic compounds as a binder.

5. A fireproofiing composition comprising 20- 50% of the water insoluble reaction product of phosphorous oxychloride with anhydrous ammonia suspende in'80-50% of a material selected from the group consisting of polyvinyl acetate emulsion, polystyrene emulsion, synthetic and natural rubber latexes and alkyd resin emulsion as binders.

6. An article of manufacture comprising a mass of fibrous material fireproofed by the addition of the water insoluble reaction product of phosphorous oxychloride with anhydrous ammonia in the proportion of 10-80% of the weight of the article.

"7. An article of manufacture comprising a mass of fibrous material fireproofed by the composition of claim 3. I

8. An article of manufacture comprising a mass of fibrous material fireproofed by the composition of claim 4.

9. An article of manufacture comprising a mass of fibrous material fireproofed by the composition of claim 5. Y

10. A glowproofingcomposition comprising polyvinyl chloride and the water insoluble reaction product of phosphoryl chloride with anhydrous ammonia.

11. A glowproofing composition comprising polyvinyl acetate and the water insoluble reaction product of phosphoryl chloride with anhydrous ammonia.

JOHN TRUHLARJ ATHAN A. PANTSIOS.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

1. A FIRE PROOFING PAINT COMPRISING 20-50% OF THE WATER INSOLUBLE REACTION PRODUCT OF PHOSPHOROUS OXYCHLORIDE WITH ANHYDROUS AMMONIA AND 80-50% OF NORMAL PAINT INGREDIENTS INCLUDING A PIGMENT AND A VEHICLE AND A BINDER. 